This invention relates to the dispensing of one or more volatile active air materials from a candle product. More specifically, this invention relates to a process for manufacturing a compression-molded candle product having multiple layers, each having a different color or appearance. Optionally one or more additives may be included in each layer. The additive may be a fragrance, sanitization agent, deodorant, insect control compound or any other volatile material, or mixture thereof which is desired to be distributed and which may be combined with the fuel of the candle. When the additive is a fragrance it is preferred that no two immediately adjacent layers of the candle contain the same fragrance.
Candles have been known and used since early civilization. A typical wax candle is formed of solid or semi-solid body of a fuel source, generally wax such as petroleum derived wax or a burnable synthetic polymer and contains an axially embedded combustible wick.
Candles have become a very popular popular form for the delivery of active ingredients, generally fragrances in recent years. Candles are offered that appeal to both the olfactory as well as the visual sense. This type of candle usually incorporates fragrance oil in the wax body. As the wax is melted in the lighted candle, fragrance oil is released from the liquefied wax pool.
Candles which offer a single fragrance have been offered for several years and have exhibited enormous consumer appeal. Likewise, poured candles having multiple colored layers which sometimes offer a variety of scents in a single form have been sold in the consumer market and have been met with success. One of the problems with producing poured multilayered candles is the time necessary for heating and cooling the solid fuel, generally wax, since each layer must be individually poured and then cooled before an adjacent layer is added. This increases production time, and energy requirements if artificial cooling methods are used to decrease production time. These problems limit the commercial production of multi-layered candles by pour techniques.
Conventional poured fragrance candles have drawbacks and other limitations. Candles are typically prepared by means of melt processing. Wax compositions containing fragrance must be carefully developed and processed to assure a suitable release of fragrance oil from the liquefied wax pool. This process can be difficult and resource intensive. Moreover, candles made with more than one fragrance layer utilizing melt-processing technology are limited to the same drawbacks of cost and other limitations. Clearly, if a technique could be developed for the manufacture of multilayered candles by a compression technique which would be less energy intensive, more adaptable to producing large scale quantities, and which candles would provide the esthetically pleasing multi-colored layers optionally containing a volatile active ingredient for the visual sense now found in poured candles, it would be an advance in the art. Preferably such a candle would contain multiple layers with each layer exhibiting a different color or appearance. Most preferably such a candle includes multiple layers with each layer exhibiting a different color or appearance, and each layer containing a fragrance or perfume, with the proviso that no two adjacent layers can contain the same fragrance or perfume.
It is accordingly an object of this invention to provide to the art a method for the manufacture of a multi-layered candle product. It is another object of this invention to provide to the art a method for the manufacture of a multilayered candle product which is capable of dispersing a volatile active material such as a fragrance, insect control agent, sanitization aid, deodorant, or the like. It is yet another object of this invention to provide to the art a multilayered compression candle product which is esthetically pleasing and can be utilized for the dispersal of a volatile active material. Another object of the invention is to provide to the art a multilayered compression candle with each layer having a color different than any other adjacent layer, and each layer in addition contains a fragrance which is different than any other adjacent layer. Other objects and advantages shall become apparent from the accompanying description of the invention and examples.
The multilayered candle products of the instant invention are made by compression technique such as that exemplified in Requejo et al. U.S. Pat. No. 6,019,804 the disclosure of which is hereinafter incorporated by reference into this specification. In Requejo, wax prill containing additives such as colorants or fragrancing agents are compressed to form candle products having exceptional properties. Requejo however discloses only the formation of a candle product having one layer, or, a homogeneous candle product including only one set of additives. The wax prill used to form the candle products of Requejo can be formed for example by the techniques disclosed in U.S. Pat. No. 4,614,625 to Wilson, the disclosure of which is also hereinafter incorporated by reference into this specification.
By adding successive layers of prill into a compression candle mold, compressing the wax prill to form a wax body, and then adding an appropriate wick, a suitable multilayered compression candle product can be produced. This process will be further exemplified and explained below.
The basic process utilized to form the multilayered compression candle products of this invention includes the steps of:
a. Preparing x+1, where x is a whole number equal to or greater than 1, solid-fuel prill or powder layer mixtures, each layer mixture containing a compatible solid fuel having a particle size of from about 500 to about 2000 microns and preferably about 600-1190 microns, with the proviso that when added to the candle mold, no two immediately adjacent mixture layers will have the same color or appearance, and each layer mixture optionally containing one or more different additives from the group consisting of fragrances, insect control agents, sanitization aids, deodorants, or the like and mixtures thereof. When the additive is a fragrance it is preferred that no two adjacent mixture layers contain the same fragrance.
b. Adding the x+1 layer mixtures of step a to a candle mold in a sequential manner so that no adjacent layer mixture within the mold have the same color or appearance, each layer mixture being added to the mold in a quantity to produce a layer having a desired thickness after the compression step of step c;
c. Subjecting such layer mixtures in the mold to a compressive force to form a candle shape within the mold, said candle shape having a substantially horizontal upper surface, a substantially horizontal lower surface, and one or more vertical surfaces communicating with said upper and lower surfaces defining the candle shape, said candle shape having x+1 layers, each layer having a desired thickness;
d. Forming either during step xe2x80x9ccxe2x80x9d or thereafter one or more axially disposed vertical wick cavities within such candle shape;
e. Placing a combustible wick within each such axially disposed vertical wick cavity; such wick being placed to extend a flame sustaining distance above the substantially horizontal top of such candle to at or near the horizontal bottom layer of such candle shape; and then,
f. Recovering a multilayer compression candle.
Optionally, one or more axially disposed vertical wicks can be inserted into the candle during the compression molding process and thus, no wick cavity need be formed, or subsequent wick insertion step need to taken to produce the candles of this invention.
The solid fuel used in the preparation of the candle products of the instant invention is made from a solid fuel prill or solid fuel powder. Processes for making solid fuel prill or powder useful in candle manufacture are found in U.S. Pat. No. 4,641,625 and U.S. Pat. No. 6,109,804. The solid fuel used in this invention may be a conventional paraffin wax, natural wax, synthetic polymer or the like. Waxes useful in the subject invention should be solid at room temperature, water repellent, smooth texture, primarily hydrocarbon (hydrogen and carbon) in structure, low toxicity, low odor, combustible, and have low reactivity. Waxes useful in the invention can come from any of five major sources including animals (beeswax), plants (soy and carnauba waxes), minerals (montan wax), petroleum (paraffin wax), and materials produced by chemical synthesis (polyethylene and Fischer Tropsch).
In a preferred embodiment of this invention the solid fuel is a paraffin wax material. Paraffin wax materials of this type are well known and are available from a variety of sources and suppliers such as The International Group, Inc., Exxon/Mobil Corporation, Chevron Products Company Lubricants and Specialty Products as well as other suppliers. In a preferred embodiment of this invention the paraffin wax is a refined paraffin wax having a melting point in the range of about 130-150xc2x0 F., and a maximum oil content of about 1.0%. The amount of oil content in the paraffin is limited in that excessive amounts of oil affect the quality of the resultant compressed candle product. Such refined paraffin waxes are known to those skilled in the art, and are exemplified by IGI Paraflex 1239 from The International Group, Inc., Toronto, Ontario, Canada.
The solid fuel fuel source used in the preparation of the candle products of this invention may be formulated with additional additives. These additives may include:
a. microcrystalline wax materials having a melt point in the range of 150-170 F;
b. C14-C20 fatty acids;
c. wax crystal modifiers;
d. stability additives including ultra-violet stabilizers
e. colorants; and
f. volatile active additives from the group consisting of perfumes, deodorants, sanitization agents, and the like;
The microcrystalline wax materials are generally petroleum waxes derived from short residues (vacuum distillation residues) or by processing tank bottom wax or sucker rod wax. Typical grades show a much finer crystal structure than paraffin waxes and the ability to form smooth mixtures with oil or solvent. The lower melting grades (e.g. in range 135-145xc2x0 F.) are very flexible and adhesive, and contain a wide range of molecular types including a high proportion of xe2x80x98non-normalxe2x80x99 paraffins. These materials are utilized to improve the quality of the finished candle product, and the burn of the finished candle product. Microcrystalline wax materials are available from a number of sources. A preferred microcrystalline wax material is Bareco Victory Lite wax which is available from Bareco Products of Rock Hill, S.C. When utilized, the microcrystalline wax is generally present at a level of from about 0.5 to about 5.0 weight percent of the prill, preferably from about 1 to about 4 weight percent of the prill and most preferably from about 1.5 to about 3 weight percent of the prill. As used herein the term xe2x80x9cprillxe2x80x9d is meant to include particles of the solid fuel including powders, and is defined by the particle size ranges provided herein.
The C14-C20 fatty acid ingredient is also commercially available, usually as a mixture of fatty acids such as stearic acid, palmitic acid and oleic acid. These materials may be utilized to improve the finished candle product. The C14-C20 fatty acid may be utilized in the manufacture of the candles of this invention at a level from about 1 to about 20 percent by weight of the prill, preferably from about 3 to about 8 percent by weight of the prill, and most preferably from about 3.5 to about 6 weight percent of the prill. Fatty acids are offered for sale by a variety of manufacturers including Akzo Nobel Chemicals, Inc., Witco Corporation, Henkel Corp. Chemicals Group, and the like.
The wax crystal modifiers that may be used in the practice of this invention are generally ethylene and alpha olefin polymers and copolymers that act to modify the crystal behavior of the paraffin wax. These polymers have an ability to bind oil, thereby increasing the hardness and opacity of paraffin wax. These polymers may include ethylene-maleic anhydride copolymers, ethylene-alpha olefin copolymers, poly alpha olefins, and the like. Suitable wax crystal modifiers are available from a variety of sources. A preferred wax crystal modifier is a poly alpha olefin material sold under the trade mark Vybar(copyright) 103 which is available from The Polymers Division of Baker Petrolite Corporation, St. Louis, Mo. Those skilled in the art will be aware of the great variety of wax crystal modifiers available which may be utilized in the manufacture of the candles of this invention. The wax crystal modifiers are typically used at a level from about 0.5 to about 10 percent by weight of the prill, and preferably from about 1 to about 8 percent by weight of the prill, and most preferably from about 1.5 to about 4 weight percent of the prill or powder.
The optional stability agents include materials which act to stabilize ingredients in the candle, specifically colorants, against UV degradation.
The colorant is an optional ingredient, and can comprise one or more pigments and dyes in a quantity between about 0 to about 2 weight percent and preferably 0.00001 weight percent to about 0.01 weight percent of the prilled wax composition. A pigment constituent preferably is an organic toner in the form of a fine powder suspended in a liquid medium such as a mineral oil. A dye constituent normally is dissolved in an organic solvent such as toluene or xylene. A variety of pigments and dyes suitable for candle making are listed in U.S. Pat. No. 4,614,625. The candle product of this invention can be made with no pigment or dye so long as the color or appearance of immediately adjacent layers is distinguishable to a consumer. Likewise, it is preferred to use oil soluble dyes as the colorants for the candle of this invention since pigments, being solid, can sometimes operate to clog the wick of a burning candle. Pigments can however be used as the colorants in this invention if they are carefully selected, and used at appropriate levels where clogging can be minimized. Pigments may be used as overdips or the like to the candles of this invention where clogging is not a factor. Because the lack of a colorant will also define a different appearance of the candle product, colorant as used herein can also mean the absence of a colorant. Likewise, different levels of a colorant or a combination of colorants can be used to form different shades of a color, for example a blue dye can be used to form a powder blue color, and in greater quantity a navy blue, and the term colorant is thus also meant to include variations in the level of one or more dyes or pigments used to obtain different shades of the same color.
The preferred volatile active additive for use in the candles of this invention is an air freshener ingredient. When utilized, the volatile active may be present at a level of from about 0 to about 20 weight percent of the prill, and preferably from about 1.0 to about 10 weight percent. Most preferably, from about 2.0 to about 5.0 weight percent of the prill is composed of the volatile active ingredient. Air freshener ingredients are preferably liquid fragrances or perfumes comprising one or more volatile organic compounds which are available from perfumery suppliers such International Flavors and Fragrances, Firmenich International SA, Takasago International Corp. USA, Noville Inc., Quest Co., and Givaudan SA.
Most conventional fragrance materials are volatile essential oils. The fragrance can be a synthetically formed material, or a naturally derived oil such as oil of Bergamot, Bitter Orange, Lemon, Mandarin, Caraway, Cedar Leaf, Clove Leaf, Cedar Wood, Geranium, Lavender, Orange, Origanum, Petitgrain, White Cedar, Patchouli, Lavandin, Neroli, Rose absolute, and the like.
A wide variety of chemicals are known for perfumery such as aldehydes, ketones, esters, alcohols, terpenes, and the like. A fragrance can be relatively simple in composition, or can be a complex mixture of natural and synthetic chemical components.
A typical scented oil can comprise woody/earthy bases containing exotic constituents such as sandalwood oil, civet, patchouli oil, and the like. A scented oil can have a light floral fragrance, such as rose extract or violet extract. Scented oil also can be formulated to provide desirable fruity odors, such as lime, lemon or orange.
Synthetic types of fragrance compositions either alone or in combination with natural oils are described in U.S. Pat. Nos. 4,314,915; 4,411,829; and 4,434,306; incorporated herein by reference. Other artificial liquid fragrances include geraniol, geranyl acetate, eugenol, isoeugenol, linalool, linalyl acetate, phenethyl alcohol, methyl ethyl ketone, methylionone, isobornyl acetate, and the like.
The volatile active ingredient also can be a liquid formulation containing an insect repellent such as citronellal, or a therapeutic agent such as eucalyptus or menthol. The volatile active agent can be any material which can be incorporated into the solid fuel source and which can be volatilized by the heat of burning the solid fuel source. The volatile active may be a sanitization agent such as for example triethyleneglycol.
In selecting the additives for the multilayered candle of the invention, it is sometimes appropriate to consider having fragrances in adjacent layers be complimentary so as to cause the fragrances between successive layers to blend, or to form a fragrance release that is nonobjectionalble to one""s olfactory sense. The same is true of color selection between adjacent layers of the multilayered candle. Here too, selection of colors between adjacent layers can be important in creating a suitable esthetic appearance. Further, in the selection of actives between two adjacent layers, it is permissible within the scope of this invention to place a non-fragranced layer between two fragranced layers. The two fragranced layers between the non-scented layer may be of the same or different fragrance. When selecting colors for each layer of the multilayered candle no two adjacent layers may be of the same color, but, layers separated by a different color can be of the same color and/or fragrance. Thus, fragrance and or color can repeat, so long as the color or fragrance does not repeat in an immediately adjacent layer. It is also within the scope of this invention to create a non-scented candle, where only the color between two adjacent layers is different, and no volatile additive is present.
The candle product of the instant invention as stated above is formed by compression of solid fuel, preferably paraffin wax. In another embodiment this invention provides a process which comprises compression-molding prilled wax or powder compositions to form a multiple layered candle product which has a density about 0.80 to about 0.92 and preferably about 0.85 to 0.92 grams per cubic centimeter; wherein the prilled wax composition is a blend of ingredients comprising:
(a) between about 60 and about 95% and preferably about 70 to about 93 weight percent of refined paraffin wax having a melting point in the range of about 130xc2x0 and 150xc2x0 F. and preferably 135xc2x0 F. to about 145xc2x0 F., a maximum oil content of about 1.0%;
(b) between about 0 and 20 weight percent and preferably 1 to 3.5 weight percent of microcrystalline wax having a melt point in the range on 150 to 180xc2x0 F.;
(c) between about 2 and 20 weight percent and preferably 3 to 8 weight percent of a C14 to C20 fatty acid ingredient;
(d) between 0 and 5 weight percent and preferably 1 to 5 weight percent of a polymeric wax crystal modifier;
(e) between about 0 to 10 weight percent of a volatile active ingredient; and
(f) between about 0 and 2 weight percent of colorant ingredient; wherein the prilled wax composition has a powder density between about 0.50 and 0.65 grams per cubic centimeter.
Equipment and procedures for wax powder compression are described in publications such as xe2x80x9cPowder Compression of Candlesxe2x80x9d by M. Kheidr (International Group., 1990) incorporated by reference. Compression molding can be conducted under conditions comprising a molding force between 2000 and 4000 pounds force and preferably from 2400 to 2800 pounds. Most preferably a compression pressure between 2400 and 2600 pounds is utilized. Compression times can range between about 1 and about 20 seconds and a prilled wax temperature between 15xc2x0 C. and 25xc2x0 C.
The particle size distribution of the prilled wax composition allows for suitable properties of the final product and is described as having a powder density between about 0.50 to 0.65 grams per cubic centimeter and subsequently allows the compression molding of a multiple layered candle product to have a density between about 0.80 to 0.92 grams per cubic centimeter. This process is described in U.S. Pat. No. 6,019,804 previously incorporated herein by reference.
In another embodiment, this invention includes prilled wax compression molded candles which offer superior performance from the compression of prilled wax, which forms small uniform wax crystal compositions, that when compression molded into finished candles can provide even burning throughout the candle and well as from one layer into another.
In another embodiment, the invention provides a compression molded candle product which has an axially disposed vertical wick, or multiple axially disposed vertical wicks, which is a fused blend of ingredients comprising;
(a) between about 60 and 95% weight percent of refined paraffin wax having a melting point in the range of about 130 and 150xc2x0 F. and a maximum oil content of about 1.0%,
(b) between about 0 and 20 percent of microcrystalline wax having a melt point in the range on 150 to 180xc2x0 F.,
(c) between about 2 and 20 weight percent of a C14 to C20 fatty acid ingredient,
(d) between 0 and 5 weight percent of a polymeric wax crystal modifier ingredient;
(e) between about 0 to 10 weight percent of a volatile active ingredient, and
(f) between about 0 and 2 weight percent of colorant ingredient; wherein the prilled wax composition has a powder density between about 0.50 and 0.65 grams per cubic centimeter.
One of the essential aspects of the present invention is the manufacturing process for a prilled wax, multiple layered compression molded candle. The invention provides a compression molded candle product, which is comprised of prilled wax compositions that are arranged in an ordered fashion into individually fragranced, colored layers and has a density between about 0.80 and 0.92 gram per cubic centimeter. In another embodiment of the present invention, the candle product can have an applied coating medium (i.e. an overdip) having a thickness between 0.2 and 0.9 millimeters on the candle surface. This overdip coating medium may be smooth or textured.
Suitable coating compositions can include one or more ingredients selected from the group consisting of microcrystalline wax paraffin wax, natural wax, fatty acids and amides, polyolefins and celluloses.
In another embodiment of the present invention, the candle product can have a smooth or textured surface finish depending on how the candle is treated both in the mold, and during mold removal. A smooth finish can be obtained by applying a heat source to the compression mold while the candle is being compressed, which yields a hardness to the candle surface and having a thickness between 0.2 to 0.9 millimeters. A textured surface can be processed into the candle product as the candle is evacuated from the compression mold, or the mold utilized can be configured to leave a desired impression on the candle.
The candle product of the present invention is characterized by a superior combination of density and hardness. With respect to the combustion performance, a present invention candle product can maintain a wick flame height between 1 and 4 centimeters during the period of wick burn.
The candle product of the present invention develops a sidewall effect during combustion. The formation of sidewalls under normal wick burn conditions is to provide containment of the flame within the candle to allow for optimum air freshener ingredient release. Formation of sidewalls also gives aesthetic benefits (walls appear to glow when flame is contained inside), maintains the layered appearance through life (walls remain intact, so you can still see the multiple layers), and helps to contain the molten pool to prevent cratering. Under wick burn conditions, a molten wax concavity development in the candle matrix typically has an axial depth between 3 and 10 millimeters.
The candle product of the present invention can be in the form of a freestanding candle which may be cylindrical, oval, square, triangular, octagonal, rectangular, hexagonal or any combination or sidewall formation thereof, and of cylindrical, pyramidal, spherical, semi-spherical, egg or cube shaped and typically has a diameter between about 3.5 and about 25 cm and preferably from about 5 to about 15 cm and most preferably from about 7.4 to about 8 cm. The candle products of the instant invention can have a height between 7.5 and 25 cm, and preferably from about 10 to about 13 cm. Most preferably the candle product of the instant invention will have a height of from about 10 to about 10.5 cm. A free standing pillar candle made in accordance can exhibit a burn rate between 2 and 5 grams per hour with centrally positioned wick(s) of braided cotton, cotton/paper cotton/linen, or synthetic wick material such as rayon. A preferred wick material is cotton with or without paper braid or a paper core.
A present invention candle product can be positioned in or upon a holder or container or glass or metal or non-flammable compositions such and plastics or mineral origin, or may be positioned upon a suitable non-flammable surface.
Wicks utilized for the candles of the instant invention are available commercially. Those skilled in the art of candle making will be able to readily determine appropriate wick materials and suppliers based upon the solid fuel utilized, the volatile active ingredient included in the formulation, the desired rate of burn, and the like.
The following examples are further illustration of the present invention. The components and specific ingredients are present as being typical and various modifications can be derived in view of the foregoing disclosure within the scope of this invention.